Physics not moving in render...

Hi

I have a simple .blend file I want to render. I have a plane cloth falling onto a collision object, which I can see working in 3D view when I play it through, but when I try to render the animation, the plane cloth just stays where it is and does not move.

I have played the anim through in the timeline to get the blue line under the timeline (I am new to this, so please excuse my noob terminology!). I then choose Bake in the physics menu for the plane cloth, but it still does not move when rendering!

What am I doing wrong? I can not figure it out!

In your modifier stack, make sure the camera icon is not grayed out.